1. Field of the Invention
The present invention relates to a rear under mirror that is located near the rear window of a vehicle and reflects a lower area behind the vehicle body.
Priority is claimed on Japanese Patent Application No. 2010-113265, filed May 17, 2010, and No. 2010-102152, filed Apr. 27, 2010, the contents of which are incorporated herein by reference.
2. Description of the Related Art
Convex mirrors that are capable of reflecting a wide area by a reflecting surface having only a small surface area are widely used as the aforementioned type of rear under mirror. However, in the case of a convex mirror, the image reflected on the mirror surface is an inverted mirror image, and it is easy for a user to become confused by such an image.
Conventionally, concavo-convex mirrors having a mirror surface which is formed as a concave surface in a substantially vertical direction and as a convex surface in a substantially horizontal direction are commonly used for rear under mirrors that solve the aforementioned problem (see, for example, Patent document 1).
According to this type of conventional rear under mirror, a wide area in the vehicle width direction is reflected by the surface of the reflecting mirror that is convex in a substantially horizontal direction. In addition, an erect image that is formed by the surface of the reflecting mirror that is concave in a substantially vertical direction is able to be viewed by the user. (see, for example, Japanese Unexamined Patent Application No. S61-287842 (Patent document 1)).
However, this type of rear under mirror which uses a concavo-convex mirror for the reflecting mirror has a complex curved surface in which the mirror surface of the reflecting mirror is curved three-dimensionally. Accordingly, they require a certain depth in the front-rear direction. If the rear under mirror is installed inside the rear window glass, then further pressure is placed on the vehicle compartment space.
In order to ensure visibility, it is necessary for the reflecting mirror of a rear under mirror to have a surface area of at least a certain size. As a consequence, the length in the depth direction becomes elongated in accordance with the surface area of the reflecting mirror. However, the position at the rear end of the vehicle compartment interior is delimited by the rear window glass and the back door panel. If the length in the depth direction of a rear under mirror becomes too elongated, the area on the front side occupied by the rear under mirror expands onto the roof lining side inside the vehicle compartment.
Moreover, if the entire reflecting mirror of the rear under mirror is reduced in size, the surface area of the portion that reflects the lower area behind vehicle body becomes smaller. As a result of this, visibility is reduced.